// Copyright (c) 2002 Graz University of Technology. All rights reserved.
// 
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// 1. Redistributions of source code must retain the above copyright notice, this
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// 3. The end-user documentation included with the redistribution, if any, must
//    include the following acknowledgment:
// 
//    "This product includes software developed by IAIK of Graz University of
//     Technology."
// 
//    Alternately, this acknowledgment may appear in the software itself, if and
//    wherever such third-party acknowledgments normally appear.
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// 4. The names "Graz University of Technology" and "IAIK of Graz University of
//    Technology" must not be used to endorse or promote products derived from this
//    software without prior written permission.
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// 5. Products derived from this software may not be called "IAIK PKCS Wrapper",
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package iaik.pkcs.pkcs11.objects;

//import java.util.Collection;
import iaik.pkcs.pkcs11.Session;
import iaik.pkcs.pkcs11.TokenException;
import iaik.pkcs.pkcs11.wrapper.Constants;

import java.util.Enumeration;

/**
 * An object of this class is a generic template. Its purpose is to serve
 * as a container for a set of attributes that the application can use to search
 * for objects. This can be especially useful, if an application wants to search
 * for objects in a very restricted manner. For instance, if an application
 * wants to find all objects which contain an ID attribute with an given value,
 * it can use this class. If it would use the Key class, it would only find Key
 * objects. Moreover, objects of this class may serve as templates for object
 * creation and key and key-pair generation.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (attributes_ <> null)
 */
public class GenericTemplate extends Object {

	/**
	 * The default constructor. Creates an object with no attributes.
	 *
	 * @preconditions
	 * @postconditions
	 */
	public GenericTemplate() {
		super();
		attributeTable_.clear(); // we do not want any attributes in this object by default
	}

	/**
	 * Adds an attribute to this generic search template.
	 *
	 * @param attribute The attribute to add to the template.
	 * @preconditions (attribute <> null)
	 * @postconditions
	 */
	public void addAttribute(Attribute attribute) {
		if (attribute == null) {
			throw new NullPointerException("Argument \"attribute\" must not be null.");
		}
		//attributes_.addElement(attribute);
		attributeTable_.put(attribute.getType(), attribute);
	}

	/**
	 * Adds all attributes of the given object to this generic template.
	 * Notice that this method does not automatically clone the attributes. If the
	 * application needs this, it must clone the argument object before.
	 *
	 * @param object The object that holds the attributes to add to the template.
	 * @preconditions (object <> null)
	 * @postconditions
	 */
	public void addAllAttributes(Object object) {
		if (object == null) {
			throw new NullPointerException("Argument \"object\" must not be null.");
		}
		Enumeration newAttributeKeysEnumeration = object.attributeTable_.keys();
		while (newAttributeKeysEnumeration.hasMoreElements()) {
			java.lang.Object newKey = newAttributeKeysEnumeration.nextElement();
			attributeTable_.put(newKey, object.attributeTable_.get(newKey));
		}
		// attributeTable_.putAll(); does not exist in JDK 1.1
	}

	/**
	 * Adds all attributes of the given object which have their present flag set
	 * to this generic template.
	 * Notice that this method does not automatically clone the attributes. If the
	 * application needs this, it must clone the argument object before.
	 *
	 * @param object The object that holds the attributes to add to the template.
	 * @preconditions (object <> null)
	 * @postconditions
	 */
	public void addAllPresentAttributes(Object object) {
		if (object == null) {
			throw new NullPointerException("Argument \"object\" must not be null.");
		}
		Enumeration attributeEnumaeration = object.attributeTable_.elements();
		while (attributeEnumaeration.hasMoreElements()) {
			Attribute attribute = (Attribute) attributeEnumaeration.nextElement();
			if (attribute.isPresent()) {
				attributeTable_.put(attribute.getType(), attribute);
			}
		}
	}

	/**
	 * Create a (deep) clone of this object.
	 *
	 * @return A clone of this object.
	 * @preconditions
	 * @postconditions (result <> null)
	 *                 and (result instanceof GenericTemplate)
	 *                 and (result.equals(this))
	 */
	public java.lang.Object clone() {
		GenericTemplate clone = (GenericTemplate) super.clone();

		clone.attributeTable_.clear(); // we do not want any attributes in this object by default

		// make a deep clone of all attributes
		Enumeration attributesEnumeration = attributeTable_.elements();
		while (attributesEnumeration.hasMoreElements()) {
			Attribute attribute = (Attribute) attributesEnumeration.nextElement();
			Attribute clonedAttribute = (Attribute) attribute.clone();
			clone.attributeTable_.put(clonedAttribute.getType(), clonedAttribute); // put all cloned attributes into the new table
		}

		return clone;
	}

	/**
	 * Checks, if the given attributte is in this template. More precisely, it
	 * returns true, if there is any attribute in this template for which
	 * attribute.equals(otherAttribute) returns true.
	 *
	 * @param attribute The attribute to look for.
	 * @return True, if the attribute is in the template. False, otherwise.
	 * @preconditions (attribute <> null)
	 * @postconditions
	 */
	public boolean containsAttribute(Attribute attribute) {
		if (attribute == null) {
			throw new NullPointerException("Argument \"attribute\" must not be null.");
		}
		return attributeTable_.containsKey(attribute.getType());
	}

	/**
	 * Compares all member variables of this object with the other object.
	 * Returns only true, if all are equal in both objects.
	 *
	 * @param otherObject The other object to compare to.
	 * @return True, if other is an instance of this class and all member
	 *         variables of both objects are equal. False, otherwise.
	 * @preconditions
	 * @postconditions
	 */
	public boolean equals(java.lang.Object otherObject) {
		boolean equal = false;

		if (otherObject instanceof GenericTemplate) {
			GenericTemplate other = (GenericTemplate) otherObject;
			equal = (this == other) || (this.attributeTable_.equals(other.attributeTable_));
		}

		return equal;
	}

	/**
	 * The overriding of this method should ensure that the objects of this class
	 * work correctly in a hashtable.
	 *
	 * @return The hash code of this object.
	 * @preconditions
	 * @postconditions
	 */
	public int hashCode() {
		return attributeTable_.hashCode();
	}

	/**
	 * Read the values of the attributes of this object from the token.
	 *
	 * @param session The session handle to use for reading attributes.
	 *                This session must have the appropriate rights; i.e.
	 *                it must be a user-session, if it is a private object.
	 * @exception TokenException If getting the attributes failed.
	 * @preconditions (session <> null)
	 * @postconditions
	 */
	public void readAttributes(Session session)
	    throws TokenException
	{
		if (objectHandle_ == -1) {
			throw new TokenException(
			    "Object handle is not set to an valid value. Use setObjectHandle(long) to set.");
		}

		super.readAttributes(session);

		Enumeration attributeEnumeration = attributeTable_.elements();
		while (attributeEnumeration.hasMoreElements()) {
			Attribute attribute = (Attribute) attributeEnumeration.nextElement();
			Object.getAttributeValue(session, objectHandle_, attribute);
		}
	}

	/**
	 * Removes the given attribute from the template. More precisely, it removes
	 * the attribute from the template which has the same type as the given
	 * attribute. Notice that type in this context does not refer the the type
	 * of data in the attribute's value. For instance, Attribute.SIGN is a type
	 * of an attribute.
	 *
	 * @param attribute The attribute to remove.
	 * @return The removed attribute, if the attribute was in the template.
	 *         Null, otherwise.
	 * @preconditions (attribute <> null)
	 * @postconditions
	 */
	public Attribute removeAttribute(Attribute attribute) {
		if (attribute == null) {
			throw new NullPointerException("Argument \"attribute\" must not be null.");
		}

		return (Attribute) attributeTable_.remove(attribute.getType());
	}

	/**
	 * Removes all attributes of the given object from this generic template.
	 * More precisely, it removes the attributes from the template which have the
	 * same type as an attribute of the given object.
	 * Notice that type in this context does not refer the the type
	 * of data in the attribute's value. For instance, Attribute.SIGN is a type
	 * of an attribute.
	 *
	 * @param object The object that holds the attributes to add to the template.
	 * @preconditions (object <> null)
	 * @postconditions
	 */
	public void removeAllAttributes(Object object) {
		if (object == null) {
			throw new NullPointerException("Argument \"object\" must not be null.");
		}
		Enumeration keysToRemove = object.attributeTable_.keys();
		while (keysToRemove.hasMoreElements()) {
			attributeTable_.remove(keysToRemove.nextElement());
		}
	}

	/**
	 * Removes all attributes of the given object which have their present flag
	 * set from this generic template.
	 * More precisely, it removes the attributes from the template which have the
	 * same type as an attribute of the given object.
	 * Notice that type in this context does not refer the the type
	 * of data in the attribute's value. For instance, Attribute.SIGN is a type
	 * of an attribute.
	 *
	 * @param object The object that holds the attributes to add to the template.
	 * @preconditions (object <> null)
	 * @postconditions
	 */
	public void removeAllPresentAttributes(Object object) {
		if (object == null) {
			throw new NullPointerException("Argument \"object\" must not be null.");
		}
		Enumeration keysToRemove = object.attributeTable_.keys();
		while (keysToRemove.hasMoreElements()) {
			Attribute attribute = (Attribute) object.attributeTable_.get(keysToRemove
			    .nextElement());
			if (attribute.isPresent()) {
				attributeTable_.remove(attribute);
			}
		}
	}

	/**
	 * Set the present flags of all attributes of this object to the given value.
	 *
	 * @param present The new value for the present flags of all attributes.
	 * @preconditions
	 * @postconditions
	 */
	protected void setAllPresentFlags(boolean present) {
		// make a deep clone of all attributes
		Enumeration attributesEnumeration = attributeTable_.elements();
		while (attributesEnumeration.hasMoreElements()) {
			Attribute attribute = (Attribute) attributesEnumeration.nextElement();
			attribute.setPresent(present);
		}
	}

	/**
	 * This method returns a string representation of the current object. The
	 * output is only for debugging purposes and should not be used for other
	 * purposes.
	 *
	 * @return A string presentation of this object for debugging output.
	 * @preconditions
	 * @postconditions (result <> null)
	 */
	public String toString() {
		return toString(false, true, Constants.INDENT);
	}

	/**
	 * This method returns a string representation of the current object.
	 * Some parameters can be set to manipulate the output. The output is
	 * only for debugging purposes and should not be used for other
	 * purposes.
	 *
	 * @param newline		true if the output should start in a new line
	 * @param withName	true if the type of the attribute should be returned too
	 * @param indent		the indent to be used
	 * @return A string presentation of this object for debugging output.
	 * @preconditions
	 * @postconditions (result <> null)
	 */
	public String toString(boolean newline, boolean withName, String indent) {
		StringBuffer buffer = new StringBuffer(1024);

		Enumeration attributesEnumeration = attributeTable_.elements();
		boolean firstAttribute = !newline;
		while (attributesEnumeration.hasMoreElements()) {
			Attribute attribute = (Attribute) attributesEnumeration.nextElement();
			if (attribute.isPresent()) {
				if (!firstAttribute) {
					buffer.append(Constants.NEWLINE);
				}
				buffer.append(indent);
				buffer.append(attribute.toString(withName));
				firstAttribute = false;
			}
		}

		return buffer.toString();
	}

}
